Photographic emulsions containing couplers and hydrosols



Nov. 27, 1956 K. J. TONG 2,772,163

PHOTOGRAPHIC EMULSIONS CONTAINING COUPLERS AND HYDROSOLS Filed April 17, 1955 l2 l3 COUPLER SILVER HAL/DE GELATl/V HYDROSOL SUPPORT YELLOW COUPLE R SILVER HAL/OE BLUE SENS/77VE PM 75/? 7, l8 #MAGE/VTA COUPLER l6 SILVER HAL/DE-GREEN .SE/VS/T/l/E GELATl/V HYDROSOL cm/v COUPLER \S/LVER HAL/OE RED SENSITIVE GELA Tl/V HYOROSOL LEE KARL JAN TO/VG INVENTOR.

ATTORNEYS United States Patent PHOTOGRAPHIC EMULSIONS CONTAINING COUPLERS AND HYDRQSOLS Lee Kari Jan Tong, Rochester, N. Y., assignor to Eastman Kodak Company, Rochester, N. Y., a corporation of New Jersey Application April 17, 1953, Serial No. 349,348

7 Claims. (Cl. 96-97) This invention relates to photography and particularly to a method of incorporating color-forming compounds in photographic emulsions.

It is Well known that coupler compounds capable of coupling with the oxidation product of primary aromatic amino developing agents may be incorporated in'photographic gelatin or silver halide emulsions in a variety of ways depending upon the solubility characteristics of the couplers-and their intended use. Couplers which are solu'ble or partially soluble in water or aqueous systems may be incorporated directly in gelatin usuallyas the alkali metal salt, as described in Fischer, U. S. Patent 1,102,028. Couplers which are soluble in oils or organic solvents may first be mixed with a solvent for the coupler and the solution dispersed in the gelatin as described in Mannes and Godowsky, U. S. Patent 2,304,940, and Ielley and Vittum, U. S. Patent 2,322,027. However, certain couplers of intermediate solubility are not sufiiciently soluble in aqueous systems to permit their incorporation directly in the gelatin nor are they sufiiciently soluble in organic solvents so that satisfactory amounts can be incorporated in organic coupler solvents.

It is therefore an object of the present invention to provide a novel method for dispersing or incorporating couplers in hydrophilic colloid layers or silver halide emulsions. A further object is to provide for incorporating couplers of lower solubility in organic solvents in photographic emulsions. A still further object is to provide a method permitting increased amounts of coupler to be dispersed in photographic emulsions. Other objects will appear from the following escription of my invention.

These objects are accomplished by including in the hydrophilic colloid-coupler mixture a latex or hydrosol of a water-insoluble synthetic polymer including at least an ester of acrylic acid or methacrylic acid with an aliphatic acid having not more than 10 carbon atoms.

In the accompanying drawing, Figure 1 is a sectional view of a single layer film according to my invention and Figure 2 is a sectional view of a multilayer photographic film constructed according to my invention.

My invention is concerned principally With the incorporation of couplers or color-forming compounds in 'gelatino-silver halide emulsions although silver halide 2,772,163 Patented Nov. 27, 1956 "ice to the silver halide emulsion. The solution of coupler may, however, be mixed with the silver halide emulsion and the latex or hydrosol then added. The resulting emulsion containing the coupler and the latex or hydrosol is then coated and dried in the usual Way. The coupler appears in finely dispersed. solid particles and the resin latex is completely compatible with the gelatin or other hydrophilic colloid forming a uniform smooth layer of the colloid.

The latex or hydrosol which constitutes the essential feature of my invention is a colloidal suspension in water of a synthetic polymer including at least an ester of acrylic or methacrylic acid with an aliphatic alcohol having not more than 10 carbon atoms. Suitable esters include methylacrylate, ethylacrylate, n-propyl acrylate, isopropyl acrylate, n-butylacrylate, methyl methacrylate, ethyl methacrylate, etc. These may be copolymerized with nitriles, e. g., acrylonitrile, or with styrene or substituted styrenes, e. g., o-methyl styrene, 2,4-din1ethyl styrene, 2,4,5-trimethyl styrene, o-ethyl styrene, etc. Three component polymers may be made by copolymerizing the acrylic or methacrylic acid esters with nitriles or styrenes and acrylamide or methacrylamide or alkyl substituted derivatives of acrylamide or methacrylamide.

The latex or hydrosol is produced by polymerizing or copolymerizing the monomer or monomers in water or other aqueous system. The method of preparing the hydrosol is not part of my invention but is the invention of William F. Fowler, Jr. and is described in his U. S. Patent 2,739,137. Any of the monomers referred to in that application may be used in preparing the hydrosols which I use.

The objects and uses of my invention may be more fully illustrated by reference to the following specific examples.

EXAMPLE 1 This example illustrates the incorporation of Waterinsoluble couplers in silver halide emulsions.

A hydrosol prepared by the emulsion polymerization of a mixture of 58.8% n-butyl acrylate, 25.2% styrene and 16% methacrylamide as described in Fowler U. S. Patent 2,739,137 using persulfate catalysts and sodium lauryl sulfate as the dispersing agent was diluted to 20% solids concentration. To grams of this dispersion there was added 1.0 gram of the coupler N-(p-benzoylacetaminobenzenesulphonyl) N ('y phenylpropyD- (o)-, (m)-, or (p)-toluidine and mixed for two days. The excess undissolved coupler was removed by filtration through Whatman filter paper No. 2.

The coupler dispersion was mixed with an equal volume of gelatino-silver halide emulsion containing 17 grams of silver halide per liter of emulsion. After mixing for /2 hour the emulsion was coated on a cellulose acetate supportand dried in the usual way. The coating was clear and showed particles of coupler but no particles of resin upon microscopic examination at 800 diameters.

When dry the coating was exposed through a gradation exposure tablet and developed at 68 F. for 10 minutes in a developer of the following composition:

Grams 2-amino-5-diethylamino toulene HCl 2 Sodium sulfite (anhydrous) 2 Sodium carbonate, monohydrate 20 Potassium bromide 2 Sodium hydroxide to give pH 10.8, Water to 1 liter.

The coating showed that an appreciable amount of (3) 5 1160 yellow dye had been developed in accordance with the I exposure. 0 ONHGOOCQEM (t.)

If the coupler were dispersed with wetting agents alone in the absence of the polymeric hydrosol, most of the 5 I coupler particles Would be too large to pass through the filter paper, and little or noyellow dye would be produced on exposure and processing of the emulsion prepared with such filtrate.

In a similar manner the magenta couplers of U. S. Patent 2,369,489 and the cyan couplers of U. S. Patent 2,423,730 were incorporated in emulsions; GH GOOH This example was l'ePeated using the same hydrosol 1-hydroxy-3-carbethoxy-4-[4-(carboxymethyl)phenylazo]-4- but preswelled with 5 cc. benzene per 100 cc. of hydrosol 15 amylphenoxy)'z'naphthanmde before incorporation of the couplers. (4) OH 700011 In addition to the couplers referred to in Example 1 the NH 1 following additional couplers may be used according to a 00 my invention, this list being illustrative only. V 0

( 1) ame.) i N=N 05H 0 ONE 0005mm.) 1 I l-hydroxy- [3-carbethoxy-4'- (2 ",4"-di-tert. amylphenoxy) ]-2- 01120 O O H naphthanilide 1hydroxy-5'-carbethoxy-4 [4- (carboxymethyl) phenylazo] -2- (2,4-di-tert. amylphenoxy) -2-naphthan111de (5) somnomon 20H N=oNHoo NBC 0 I NHOO SOQNHCHZGHZOH Cs u l phenyl- 3-{3 [2',4"' di-tert. amylphenoxy) 5 3f.,

5' di N B hydroxyethylsulfamylbenzamido)benzamldo] benzamid0}-5-pyrazo1one OH (i7 0 OH (6) CONE-Q OH 7 NBC 0 a 0 O1 N'HOO SOzNHCHaGHaQH 05111102.) 7 H3O O V K C1 C2Hu s n l a A I-hydroXy-[2- (2",4-di-tert. amy1phenoxy)-5'-carboxy]-2- OsHu p hanilide 2,4=dich1orO-6-{2'- [2 ,4-di-tert. amylphenoxy] 5- [3"-N-B-hy- 6O droxyethylsulfamyl) benzamido] benzamido}-3-methy1phenol amnion C EH11 1-pheny1-3- [3'- (m-chlorosulfonyl benzamido benzamido-5- pyrazolone lITHCO /N=C NBC I C-CH:

EXAMPLE. 2

This example illustrates the use of couplers which are water-insoluble or have low solubility in water. The solubility of such couplers in the gelatin/emulsion may be increased by the use of the hydrosols according to myinvention. e

To 0.5 millimole of compound 1 there was added 151cc. of ethyl alcohol and 0.75 cc. of aqueous sodium hydroxide solution. When dissolved, 20 cc. of the hydrosol described in Example 1 (20% solids). was added. The mixture was.

neutralized'with 2.5 %.acitric acid.to pH 6.5. 'Afterzthe addition of 1.5 cc. of saponin solution and 25 cc. of-g'ela tinc-silver halide emulsion containing 17 grams of silver halide per liter of emulsion, the mixtures were coated.

' After drying and processing as described in Example 1 the film [coatings yielded clear uniform dye images. An emulsion made similarly but using 20 cc. of water instead I .01...20 -.,cc'. of the hydrosol was found to have precipitated V the couplerafter the neutralization;

EXAMPLE 3 :This example illustrates-prevention of viscosity increase of emulsions containing soluble couplers.

To 0.5 millimole of compound 8 there was :added 1.5 cc. of ethyl alcohol and 0.75 cc. of 20% aqueous sodium hydroxide solution. When the coupler was completely dissolved, the solution was partially neutralized with 5 cc. of 2.5% citric acid. Then 9.5 cc. of the hydrosol described in Example 1 (diluted to 7.5 solids) was added and the neutralization was continued with 2.5 citric acid to pH 6.5. Finally there were added 4 cc. ofwater, 9.5

'7 cciof-fge latino-silver, halide emulsionof the composition used in Example 2 and 1.5 cc. of saponin solution. Upon coating and drying in the usual way and processing as describedin Example 2, a clear uniform yellow dye image was obtained. The viscosity of the coating mixture was hydroxide solution. When the coupler was dissolved the of a hydrosol containing 70% butyl acryl'ate and 30% styrene (solids content was then added and the mixture neutralized with 2.5% citric acid to pH 6.5. The resulting dispersion was mixed with :ccr'ofira gelatino=silverhalide emulsiomof 'the composition usedfimEir- I ample 1, and the mixture coated on film base and dried in the usual way and interlayer diffusion was tested in the following manner. V p 1 Over the dried emulsion there was coated a mixture of 25 cc. of emulsion Without coupler or hydrosol and 0.6 cc. of 10% tartrazine solution. After setting and drying,

the film was exposed behind a step tablet having 20 steps of .15 density difference between steps in a totallength of /2".' The exposure-was predetermined to give after development a silver image in the top layer varying across the scale from a very light'image attheextr'emebuter surface to a heavy deposit almost completely through the top layer. The coating was then processed for 15 minutes at 70 F. in the following developer.

. a Grams 2-amino-5-diethylamino. toluene HCl 2 Sodium sulfite 2 Sodium. .carbonate, 1nonohydrate 20 V Potassium:.-.bromide-: 2" p 7 Sodium hydroxide to give pH 12. 7 Water to 1 liter.

' Water to 1 liter.

The film was then fixed for 10 minutes in a mixture of 1 part of the following hardener solution to 4 parts of 30% hypo solution. 7

Sodiums ulfite (desiccated) Q; grams Acetic :acid (28%) ..cc 235 Boric acid crystals gnams 37.5

Potassium alum 7 do 75 After washing the film and bleaching for 5 minutes in a solution of 50 grams of potassium ferricyanide and 20 grams of potassium bromide in 1 liter of water, the film was fixed for 5 minutes in 30% hypo solution and washed. When the film was dry a section of about 10 microns thickness was cut and examined microscopically at 500 diameters.

ing not containing the hydrosol, wandering of the coupler into the top layer of the coating was found to be consider- :ably reduced.

EXAMPLE 5 To 0.5.millimole of compound 14 that was added 1.5 cc. of'ethyl alcohol and 075' cc. of 20% aqueous sodium hydroxide solution. When the coupler was dissolved, 18.5

cc..of hydrosol of the composition used "in Example '4 (diluted to 7.5% solids) was added and themixture neutralized with 2.5 citric acid to pH 6.5. The dispersion was then mixed with 18.5 cc. of gelatino-silver halide emulsion, coated and tested as in Example 4. When tested 7 in this way, wandering of the coupler was found to have been reduced to 15% from a value of 30% when no hydrosol was used in the emulsion.

The various "couplers referred to herein are prepared as follows.

Compounds 1 and 3 are described in Graham, V-ittum and Weissberger, U. S. Patent 2,725,292.

When the coating was compared with a similar coat- Compounds 2 and 4 were prepared as follows:

Sixteen parts of 3-amino-4-(2,4-di-tert-amylphenoxy)- benzoic acid and 12 parts of phenyl l-hydroxy-Z-naphthoate were heated in an oil bath for one hour at 150200 C., phenol being removed at reduced pressure. Compound 2 was crystallized from acetic acid, a solid melting at 259-261 C. being obtained.

Eight parts of p-aminophenylacetic acid was diazotized in the usual way with 20 volumes of concentrated hydrochloric acid and 4 parts of sodium nitrite. The cold (0) diazonium solution was added to that of 27 parts of 1 hydroxy 5 carboxy 2 (2,4 di tert amylphenoxy) 2 --naphthanilide, dissolved in 1000 volumes of pyridine and 1000 volumes of alcohol, and cooled to 0 C. The colored solution was drowned in 10,000 volumes of water containing 200 volumes of concentrated hydrochloric acid. The precipitated product, Compound 4, was isolated on a funnel, washed with water, and crystallized from acetic acid. A solid melting at 205210 C. was obtained.

Compounds 5, 6 and 7 are described in Salminen and Weissberger, U. S. application Serial No. 344,884, filed March 26, 1953, now U. S. Patent 2,710,803.

' Compound 8 is described in McCrossen, Parmerter and Weissberger, U. S. application Serial No. 301,962, filed July 31, 1952, now U. S. Patent 2,652,329.

Compound 9 is prepared as follows:

2,4-dichl0r0-3-methyl-6-[3-nitr0-6'-(2",4"-di-tert.- amylphenoxy) benzamido] phenol In a 5-1., 3-necked flask provided with a stirrer and a thermometer was placed 1380 cc. of acetic acid. To it were added 138 g. (1.64 moles) of anhydrous sodium acetate, 138 g. (0.6 mole) of 2-amino-4,6-dichloro-S-methyl phenol hydrochloride and 264 g. (0.63 mole) of 2-(2,4'- di-tert.-amylphenoxy)-5-nitrobenzoyl chloride. The heat of reaction raised the temperature about 8 C. The slurry was stirred vigorously for 1 hour. At no time did the solid go completely into solution. The slurry was then washed into a 12-1. flask with 7.5 1..of water and the aqueoussolution was filtered on a 37-cm. Lapp table-top funnel. The product was washed on the funnel with 9 1. of ethyl alcohol and dried. The yield was 356 g. (102% M. P. 194l97 C. The product was then recrystallized from 9 l. of 97% acetic acid, filtered through the tabletop funnel, washedon the funnel with 900 cc. of acetic acid and two 1800-cc. portions of petroleum ether. The

product was air dried. The yield was 302 g. (84%); M. P. 205-207 C.

The nitro group was reduced to an amino group with powdered iron in the usual way, and the final compound .formed as follows:

In a 12-1. flask was placed 1500 cc. of 1,4-dioxane. To this was added 163 g. (0.3 mole) of 2,4-dichloro3-methy1- 6-[3'-amino-6'-(2",4" diamylphenoxy)benzamido]phe n01 and 152 g. (0.36 mole) of 3,S-dichlorosulfonylbenzoyl chloride (including one molecule of benzene of crystallization). The temperature rose about 4 and the solution had a clear orange color. It was allowed to stand for 3 mins. and 42.3 cc. (0.36 mole) of synthetic quinoline was added. The temperature again rose about 5. The solution was allowed to stand for mins. when a creamcolored precipitate was observed. A solution of 750 cc. ofconcentrated hydrochloric acid in 7 1. of water was added with stirring to the reaction mixture and a heavy yellow precipitate was formed. This was filtered on a 37-cm. Lapp table-top funnel and washed successively with 7 l. of distilled water, 7 1. of ethyl alcohol and 7 1. of ethyl ether. The precipitate was dried. The yield was 240 g. (94% M. P. 275 C.

Compound 10 is described in McCrossen, Salminen and Weissberger, U. S. application Serial No. 301,961, filed July-31, 1952, now U. S.-Patent 2,688,544.

Compounds 11 and 12 were prepared as follows:

(A) Phenyl-1-hydroxy-4-chloro-2-naphthoate was con- 'densed at 150 C. for /2 hour with an equal molecular quantity of p-ni-tro phenethyl amine yielding l-hydroxy- N-(p-nitro phenethyl) -4-chloro-2-naphthamine.

(B) The nitro compound was reduced catalytically in the presence of Raney nickel to the amine.

(C) I-hydroxy-N-(p-amino phenethyl) 4 chloro -'2 naphthyl amide was condensed in acetic acid and sodium acetate at room temperature with an equal-molecular quantity of 2-(2,4-diamy1 phenoxy)'-5-nitro benzoyl chloride.

(D) 1-hydroxy-N-{4-[2-(2',4' diamylphenoxy) 5" aminobenzanfidoJphenethyl} 4-chloro-2-naphthamide was prepared by the catalytic reduction in the presence of Raney nickel of the nitro compound obtained in step C.

(E) The final compound was prepared by the condensation of an equal molecular quantity of 3,5-disulfobenzoyl chloride (in the case of compound 11) M13- sulfobenzoyl chloride (in :the case of compound-Bland the amine of step B in dioxane and quinoline.

The preparation of compound 13 is described in I. A. C. S. 73 (1951), page 4133.

Ten grams (0.057 mole) of 1-pheny1-3-amino-5-pyrazolone (I. A. C. S. 64 (1942), p. 2134) was stirred on the steam-bath with 10.6 g. (0.057 mole) of'm-nitrobenzoyl chloride and 7 ml. of ethyl oxalate for 20 minutes. The product, 1-pheny1-3-m-nitrobenzamido-5-pyrazclone, was broken up by refluxing and stirring with 50 ml. of ethyl alcohol, cooled, collected, and washed on the funnel with 50 ml. of 70% alcohol; 14.5 g. (78%); M. P. 215220 C. The nitro group was then reduced to the amine in the usual way using iron powder catalyst.

2- (2',4-diamylphen0xy -5-n itrobenzoic acid In a 5-1. 3-necked flask equipped with stirrer and thermometer were placed 858 g. (3.66 moles) of diamylphenol and 216 g. (3.84 moles) of potassium hydroxide pellets. The mixture was heated with stirring until. the temperatures reached 130: it was then allowed to cool to and 302 g. (1.5 moles) of 2-chloro-5-nitrobenzoic acid were added. The thick mixture was stirred and heated until the temperature reached whereupon a spontaneous reaction took place and the temperature rose to The slurry became much more fluid and'the steam from the reaction was allowed to escape through the open neck of the flask. The reaction mixture was heated with stirring for 1 /2 hrs. at 140- The melt was then stirred into 4.5 l. of benzene. When the melt had been well digested, the suspension of yellow solid was filtered 0E and discarded.

The dark brown liquid was placed in a 12-1. flask, the solution was stirred very vigorously with 3 l. of water and 600 cc. of concentrated hydrochloric acid. The aqueous layer was removed and the benzene layer was washed with 1 l. of hot water. The benzene solution was concentrated to about 2.5 1.; it was cooled to 10 for several hours or overnight. Crude 2-(2,4-diamylphenoxy)-5- nitrobenzoic acid was filtered, washed on the funnel with 700 cc. of benzene, followed by 700 cc. of petroleum ether, and dried .at 100. The yield was 350-365 g. (58- 61%); M. P. 182186, with sintering at 2-(2',4-diamylphen0xy -5-nitr0b enzoyl chloride In a 2-1. round-bottomed tared flask, equipped with an air reflux condenser were placed 200 g. (0.5 mole) of 2-(2,4'-diamylphenoxy)-5-nitrobenzoic acid and 800 cc. of thionyl chloride (distilled over quinoline). The flask was heated in a waterbath at 45 .for 2 hrs. After about 15-20 minutes the solid dissolved completely and evolution of gas proceeded briskly. The reaction mixture was allowed to stand overnight at room temperature. The excess thionyl chloride was removed at the water pump while heating onthe steam bath. A viscous, honeycolored, highly refractive liquid remained. Heating was continued for 1 /2 hrs. under reduced pressure (10 mm./Hg). The viscous acid chloride was transferred stirred for 1.5 hours.

In a 2-1. round-bottomed flask equipped with a stirrer was placed 850 cc. of 95% acetic acid and in it was dissolved 32.8 g. (0.39 mole) of anhydrous sodium acetate. 'To this solution was added 58.8 g. (0.2 mole) of 1-phenyl-3-(3'-aminobenzamido)-5-pyrazolone and 96.2 g. (0.23 mole) of 2-(2',4-di-tert.-amylphenoxy)- -nitrobenzoyl chloride; The resulting solution was The temperature rose about 7 at the outset of the reaction, then gradually descended to room temperature. After or minutes, the product began to separate. After stirring was complete, the

nitro compound was filtered 011? and washed on the funnel with 600 cc. of 95 acetic acid followed by 600 cc.

of Water and 300 cc. of ethyl alcohol. The product was air dried. Yield80 g. (60% of theory), M. P.

l538. The nitro group was then reduced to the amine in the usual way using powered iron catalyst.

(2"-sulf0benzamide) benzamido]benzamido}-5-pyraz0- lone In'a 5-1. round-bottomed, three-necked ground glass jointed flask was placed 2.4 liters of histological xylene. 400 cc. of this xylene were distilled ofl (to remove water) using a Glas-col mantle. During this distillation g, (0.075 mole) of l-phenyl-3-{3'-[2"(2"',4'ditert. amylphenoxy) 5" aminobenzamido]benzamido}- 5-pyrazolone was added to the boiling xylene and dissolved by the completion of the distillation.

The flask was removed from the mantle, placed on a steam bath and equipped with a stirrer and dropping funnel. 14.3 g. ,of freshly prepared o-sulfobenzoicanhydride was dissolved in 100 cc. of hot dry xylene and added rapidly to the vigorously stirred amine solution. The temperature was maintained at 90-95 and the stirring was continued for one hour.

The reaction mixture was cooled to room temperature and filtered The solid product was washed well with dry xylene and dry ethyl ether and dried in air at 5060. A time white powder resulted. Yield 62 g.

The latexes or hydrosols which I use are prepared by'the polymerization of the monomers in aqueous solution. 'The preferred hydrosol is a three-component polymer of n-butylacrylate, styrene and methacrylamide,

the preparation of which is described in the Fowler U. S. Patent 2,739,137.

Other hydrosols which I may use are ahydrosol of- 70% butyl acrylate and 30% styrene and a hydrosol of 70% ethyl acrylate and 30% acrylonitrile.

In the accompanying drawing I have shown sectional viewsof a film constructed according to my invention. As shown therein Figure l is a sectional view of a single 7 metal or paper.

and emulsion layer 17 for blue-sensitive and contains 2 a, yellow-forming coupler. The same hydrosol may be used in each emulsion.

The emulsions made according to my invention may be used in single layer coatings or in multilayer coatings on supports of glass, cellulose ester, synthetic resins, Thehydrosols may also be used'in-a mixed-grain dispersion, that is, one in which a single emulsion layer contains two or more sets of silver halide grainssensitive to difierent spectral regions.

It will be understood that the examples and modifications included herein are illustrative only and that my invention is to be taken as limited onlyby the scope of the appended claims.

I claim:

1. A color-forming photographic emulsion comprising a gelatino-silver halide emulsion continuous. phase containing in said gelatin continuous phase a coupler compound capable of coupling with'the oxidation product of a primary aromatic amino developing agent and also in said gelatin continuous phase a hydrosol of a waterinsoluble synthetic polymer made by emulsion polylayer element comprising a support 10 having thereon hydrosol. g

Figure 2 is a multilayer photographic element inwhich fthe support 10 is coated with emulsion layers 15, 16 and merization, said polymer including at least anester of an acrylic acid with an aliphatic alcohol havingnot more than 10 carbon atoms.

2. A color-forming photographic emulsion comprising a gelatino-silver halide emulsion continuous phase containing in said gelatin continuous phase a coupler compound capable ofcoupling with the oxidation product of a primary aromatic amino developing agent and containing in its acid form a solubilizing group selected from the class consisting of sulfonic acid, carboxylic acid and hydroxyalkyl groups, and also in said gelatin continuous phase a hydrosol of a water-insoluble syntheticpolymer made by emulsion polymerization,

said polymer including a butyl acrylate. 7

3. The emulsion of claim 2 in which the hydrosol is a hydrosol of a water-insoluble copolymer of n-butyl acrylategstyrene and methacrylamide. V

4. The emulsion of claim 2 inwhich the hydrosol is a hydrosol of a copolymer of 58.8% by weight n-butyl acrylate, 25.2% by weight styrene and 1 6% by weight acrylamide.

5. The method of incorporating in a gelatino-silver,

halide emulsion a coupler compound capable of coupling with the oxidation product of a primary aromatic amino hydroxyalkyl groups, which comprises dissolving said coupler compound in an alkaline solution, mixing the solution of coupler compound in alkaline solution with a hydrosol of a water-insoluble synthetic polymer made.

by emulsion polymerization, saidpolymer including at least an ester of an acrylic acid with an aliphatic alcohol having not more than 10 carbon atoms, neutralizing the resulting mixture and mixing it with a gelatino-silver halide emulsion to produce dispersed particles of said hydrosol and said coupler in the emulsion.

6. The method-of incorporating in a gelatino-silver halide emulsion a coupler compound capable of coupling with the oxidation product of a primary aromatic amino developing agent on photographic development, and containing in its acid form a solubilizing group selected from the class consisting of sulfonic acid, carboxylic acid and hydroxyalkyl groups, which comprises dis- 7 solving said couplercompound in an alkaline ethyl alcohol solution, mixing the solution of coupler compound in alkaline ethyl valcohol with a'hydrosol, of a 17, a yellow filter layer 18 being imposed between layers 16 and 17. Emulsion layer 15 is red-sensitive and contains a cyan-forming coupler emulsion layer 7 16 for green-sensitive and contains a magenta-forming coupler water-insoluble copolymer made by emulsion polymerization of n-butyl acrylate, styrene and methacrylamide,

neutralizing the resulting mixture and mixing it with a gelatino-silver halide emulsion to produce dispersed particles of said hydrosol and said coupler in the emulsion.

7. The method of incorporating in a gelatino-silver halide emulsion a coupler compound capable of coupling with the oxidation product of a primary aromatic amino developing agent on photographic development, and containing in its acid form a solubilizing group selected from the class consisting of sulfonic acid, carboxylic acid and hydroxyalkyl groups, which comprises dissolving said coupler compound in an alkaline ethyl alcohol solution, mixing the solution of coupler compound in alkaline ethyl alcohol with a hydrosol of a water-insoluble copolymer made by emulsion polymerization of n-butyl acrylate and styrene, neutralizing the resulting mixture and mixing it with a gelatino-silver halide emulsion to produce dispersed particles of said hydrosol and said coupler in the emulsion.

References Cited in the file of this patent UNITED STATES PATENTS 1,981,102 Hagedorn et al. Nov. 20, 1934 14 Wilmanns et al. Jan. 9, Martinez Jan. 6, Mannes et al. Dec. 15, Jelley et al. June 15, Gaspar Nov. 7, Potter May 15, Ielley et al. Aug. 9, Yackel Mar. 7, Staehle Mar. 13,

FOREIGN PATENTS Great Britain Aug. 10, Great Britain Oct. 15, 

1. A COLOR-FORMING PHOTOGRAPHIC EMULSION COMPRISING A GELATINO-SILVER HALIDE EMULSION CONTINUOUS PHASE CONTAINING IN SAID GELATIN CONTINUOUS PHASE A COUPLER COMPOUND CAPABLE OF COUPLING WITH THE OXIDATION PRODUCT OF A PRIMARY AROMATIC AMINO DEVELOPING AGENT AND ALSO IN SAID GELATIN CONTINUOUS PHASE A HYDROSOL OF A WATERINSOLUBLE SYNTHETIC POLYMER MADE BY EMULSION POLYMERIZATION, SAID POLYMER INCLUDING AT LEAST AN ESTER OF AN ACRYLIC ACID WITH AN ALIPHATIC ALCOHOL HAVING NOT MORE THAN 10 CARBON ATOMS. 